Backdoor plugin

Would it be possible to have the plugin call a command via console>

Yes but what exactly are you trying to do with a backdoor plugin? You can't publicly release it so you would have to do it privately and the fact you ran the command is still visible in the console

Well, the main factor is if a plugin even can change the rank of someone, or even 'create' a rank called something random and give permission *

Yes it can